Medications Used for Gastrointestinal System Disorders UNIT 22 Medications Used for Gastrointestinal System Disorders

Key Terms Amebiasis Chyme Defecation GERD Helminthiasis Histamine antagonist Peptic ulcer

Common GI Complaints Ulcers GERD Dyspepsia Pyrosis Nausea and vomiting Diarrhea and constipation (continues)

Common GI Complaints Causes of GI complaints Poor diet Stress Alcohol Caffeine Smoking NSAIDs Infection with H. pylori

Helicobacter pylori 80% of gastric ulcers 90% of duodenal ulcers Diagnosis Serology for antibodies Breath test EGD Biopsy urease test (continues)

Helicobacter pylori Treatment Requires 10–14 days Antibiotics Bismuth preparations Proton-pump inhibitors Histamine antagonist

Ulcer Symptoms Gnawing or burning epigastric pain Nausea Vomiting Loss of appetite Bleeding

Changes That Affect GI Function in Older Adults Dental deterioration Weakening of muscles Difficulty swallowing Decline in taste bud function Decreased peristalsis Reduced hepatic blood flow and function

Signs of Dehydration in Children Weight loss Irritability and lethargy Loss of skin elasticity Dry mucous membranes Sunken eyes and fontanels Decreased tearing, salivation, or urination Subnormal or elevated body temperature Increased pulse or respirations

Antacids Neutralize stomach acid Most are nonsystemic Sodium bicarbonate can have systemic effect Aluminum or calcium based May cause constipation Magnesium based May cause diarrhea

Antacid Mixtures Combines aluminum or calcium compound with magnesium salts Each counters adverse effect of the other Discussion Question: What would be some potential adverse effects from long-term use of sodium bicarbonate?

Histamine H2-Receptor Antagonist Inhibit gastric acid secretion Inhibit gastric acid stimulation Adverse reactions Varies with drug Generally well tolerated Some may affect libido or sexual function Should not be used during pregnancy or breastfeeding, or for children younger than 16 years of age

Histamine Antagonist Patient Education Avoid substances and foods that cause duodenum irritation Caffeine Nicotine Alcohol Spicy foods OTC medications (aspirin) (continues)

Histamine Antagonist Patient Education Discussion Question: How would you explain to a patient the difference in action between an antacid and a histamine antagonist?

Mucosal Protective Medications Carafate Forms coating over surface of ulcer Cytotec Prevents NSAID-induced gastric ulcers Warning! Cytotec is an abortifacient, and is contraindicated during pregnancy or childbearing potential.

Proton-Pump Inhibitors Suppress gastric acid secretion Dosage varies with drug Medication should not be crushed or chewed Examples: Prilosec Aciphex Prevacid Protonix Nexium (continues)

Proton-Pump Inhibitors Warning! When clopidogrel and omeprazole are taken together, the effectiveness of clopidogrel is reduced. Patients at risk of heart attacks or strokes using clopidogrel to prevent blood clots will not get the full effect of this medicine. Discussion Question: What is the difference in action between histamine antagonists and proton-pump inhibitors?

Laxatives Bulk-forming agents Lubricants Osmotic laxatives Saline laxatives Stool softeners Stimulant laxatives (continues)

Laxatives Uses Constipation Prep for surgery or diagnostic testing After anthelmintic therapy, to speed elimination of parasites Reduction of strain of defecation for cardiac patients (continues)

Laxatives Contraindications Impaction Appendicitis Intestinal or biliary tract obstructions Acute hepatitis Third trimester of pregnancy (continues)

Laxatives Warning! Lubricant laxatives May interfere with absorption of vitamins A, D, E, and K. May increase effect of oral anticoagulants. Be alert for signs of bleeding. May produce lipid pneumonia if aspirated.

Laxative Abuse As with any other drug, laxatives can be abused. Causes colon to become lazy, causing true constipation Slowly reduce laxative use until return to normal state Increase fluids, fiber, and exercise

Antidiarrheal Agents Avoid salicylates with Pepto-Bismol Lomotil is schedule V controlled substance Do not use Lomotil with MAO inhibitors Imodium contraindicated for patients with severe ulcerative colitis and pseudomembranous enterocolitis (continues)

Antidiarrheal Agents Discussion Questions: Why should patients avoid ASA while taking Pepto-Bismol? Why is Lomotil a controlled substance? How does this help control diarrhea?

Diarrhea Facts Diarrhea is a symptom, not a disease May be acute or chronic May result in dehydration and electrolyte imbalance May be caused by infection, allergy, tumors, food poisoning, intoxication, malabsorption, or medications

Anthelmintics Helminthiasis is intestinal infestation by parasitic worms Nemathelminthes Roundworms Platyhelminthes Flatworms Associated with unsanitary living conditions Can be treated with anthelmintic medication (continues)

Anthelmintics Discussion Questions: What are some ways to prevent helminthiasis? Who are some people who would be at risk in the United States of helminthiasis?

Protozoal Infections Often found in developing countries Travel and military increase incidence in United States Malaria Giardiasis Trichomoniasis Amebiasis

Antiprotozoal Agents Dosage varies with drug Flagyl and Yodoxin used for both trichomoniasis and amebiasis

Antiemetics Agents that prevent or arrest vomiting Treatment of Vertigo Motion sickness Nausea associated with antineoplastic agents and radiation

Emetics Induce vomiting Contraindicated if ingested caustic substances Activated charcoal given after vomiting stops Warning! Always have the phone number to poison control nearby. (continues)

Emetics Apomorphine HCl Ipecac syrup Onset in 2–10 minutes Best on full stomach Ipecac syrup Available OTC Onset within 20 minutes Follow with water